[PATCH v5 0/3] Add SSIF BMC driver

From: Quan Nguyen
Date: Tue Jul 13 2021 - 23:38:58 EST


This series add support the SSIF BMC driver which is to perform in-band
IPMI communication with their host in management (BMC) side.

SSIF BMC driver in this series is tested with Aspeed AST2500.

v5:
+ Correct the patches order to fix the bisect issue found by
kernel build robot

v4:
+ Fix recursive spinlock [Graeme]
+ Send response with Completion code 0xFF when aborting [Quan]
+ Fix warning with dt_binding_check [Rob]
+ Change aspeed-ssif-bmc.yaml to ssif-bmc.yaml [Quan]
+ Added bounding check on SMBus writes and the whole request [Dan]
+ Moved buffer to end of struct ssif_bmc_ctx to avoid context
corruption if somehow buffer is written past the end [Dan]
+ Return -EINVAL if userspace buffer too small, dont
silence truncate [Corey, Joel]
+ Not necessary to check NONBLOCK in lock [Corey]
+ Enforce one user at a time [Joel]
+ Reject write with invalid response length from userspace [Corey]
+ Add state machines for better ssif bmc state handling [Quan]
+ Drop ssif_bmc_aspeed.c and make ssif_bmc.c is generic
SSIF BMC driver [Quan]
+ Change compatible string "aspeed,ast2500-ssif-bmc" to
"ampere,ssif-bmc" [Quan]
+ Toggle Slave enable in i2c-aspeed to turn on/off slave mode [Ryan]
+ Added slave_enable() to struct i2c_algorithm to control
slave mode and to address the recursive spinlock [Graeme, Ryan]
+ Abort current request with invalid SMBus write or
invalid command [Quan]
+ Abort all request if there is pending response [Quan]
+ Changed validate_pec() to validate_request() [Quan]
+ Add unsupported_smbus_cmd() to handle unknown SMBus command [Quan]
+ Print internal state string for ease investigating issue [Quan]
+ Move to READY state on SLAVE_STOP event [Quan]
+ Change initilize_transfer() to process_smbus_cmd() [Quan]
+ Introduce functions for each slave event [Quan]

v3:
+ Switched binding doc to use DT schema format [Rob]
+ Splited into generic ssif_bmc and aspeed-specific [Corey, Joel]
+ Removed redundant license info [Joel]
+ Switched to use traditional if-else [Joel]
+ Removed unused ssif_bmc_ioctl() [Joel]
+ Made handle_request()/complete_response() to return void [Joel]
+ Refactored send_ssif_bmc_response()/receive_ssif_bmc_request()
[Corey]
+ Remove mutex [Corey]
+ Use spin_lock/unlock_irqsave/restore in callback [Corey]
+ Removed the unnecessary memset [Corey]
+ Switch to use dev_err() [Corey]
+ Combine mask/unmask two interrupts together [Corey]
+ Fixed unhandled Tx done with NAK [Quan]
+ Late ack'ed Tx done w/wo Ack irq [Quan]
+ Use aspeed-specific exported aspeed_set_slave_busy() when slave busy
to fix the deadlock [Graeme, Philipp, Quan]
+ Clean buffer for last multipart read [Quan]
+ Handle unknown incoming command [Quan]

v2:
+ Fixed compiling error with COMPILE_TEST for arc

Quan Nguyen (3):
i2c: aspeed: Add slave_enable() to toggle slave mode
ipmi: ssif_bmc: Add SSIF BMC driver
bindings: ipmi: Add binding for SSIF BMC driver

.../devicetree/bindings/ipmi/ssif-bmc.yaml | 38 +
drivers/char/ipmi/Kconfig | 11 +
drivers/char/ipmi/Makefile | 1 +
drivers/char/ipmi/ssif_bmc.c | 781 ++++++++++++++++++
drivers/char/ipmi/ssif_bmc.h | 106 +++
drivers/i2c/busses/i2c-aspeed.c | 20 +
include/linux/i2c.h | 2 +
7 files changed, 959 insertions(+)
create mode 100644 Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml
create mode 100644 drivers/char/ipmi/ssif_bmc.c
create mode 100644 drivers/char/ipmi/ssif_bmc.h

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2.28.0